The technique of hydraulic fracturing (commonly referred to as “fracing” or “fracking”) is used to increase or restore the rate at which fluids, such as oil, gas or water, can be produced from a reservoir or formation, including unconventional reservoirs such as shale rock or coal beds. Fracing is a process that results in the creation of fractures in rocks. The most important industrial use is in stimulating oil and gas wells where the fracturing is done from a wellbore drilled into reservoir rock formations to increase the rate and ultimate recovery of oil and natural gas.
Hydraulic fractures may be created or extended by internal fluid pressure which opens the fracture and causes it to extend through the rock. Fluid-driven fractures are formed at depth in a borehole and can extend into targeted formations. The fracture width is typically maintained after the injection by introducing a proppant into the injected fluid. The fracturing fluid has two major functions, to open and extend the fracture; and to transport the proppant along the length of the fracture.
Current fracing systems and methods, however, are expensive and inefficient.
In many cases, it is desired to target the fracturing fluid at a specific location in a formation. Prior attempts to address this issue include the devices and methods disclosed in Canadian Patent Application 2,755,848 and Canadian Patent 2,692,377, both of which are hereby incorporated by reference in their entirety.
Both of these documents disclose a burst opening for fracing fluid to exit the completion/service string and access the formation. Application 2,755,848 teaches a “projectile core” in the burst opening. In practice, it was discovered that the dislodged projectile can actually worsen the performance of the tool by blocking fluid flow outside of the tool.
Safer, more productive, and cost-effective fracing methods and systems are quickly becoming sought after technology by oil and natural gas companies. It is, therefore, desirable to provide an apparatus and method for hydraulic fracturing that overcomes the shortcomings of the prior art. Accordingly, there is a need to provide a safer, more productive, and more efficient fracing apparatus and method.